Throttle control mechanism for a carburetor

Abstract

A control mechanism for a carburetor having a throttle valve and a choke valve each of which valves has an idling position, a cold-starting position and a full-speed position. The throttle valve is spring-biased towards its idling position and the choke valve is spring-biased towards it full-speed position. Control levers are associated with the respective valves whereby when the choke valve is moved from its idling position towards it full-speed position, a lever member associated with the choke valve engages another lever member associated with the throttle valve and the interengaging lever members hold both valves in their cold-starting position in opposition to the biasing springs. From the cold-starting condition the lever members can be released by operation of the throttle valve causing the choke valve to be returned to its open position by its biasing spring or alternatively the choke valve can be moved independently to its full-speed position by a further control lever while the lever members remain in engagement.

What I claim is: 
     
       1. A control mechanism for a fuel/air mixing apparatus having a throttle valve and a choke valve, said valves each having an idling position, a cold starting position and a full speed position, said control mechanism including first biasing means biasing said throttle valve toward its idling position, second biasing means biasing said choke valve toward its full speed position, interengageable means associated with the respective valves for holding both valves in their cold starting positions in opposition to the biasing means upon movement of said choke valve from its idling position toward its full speed position and further means associated with the throttle valve for releasing said interengageable means by movement of the throttle valve from its cold starting position toward its full speed position. 
     
     
       2. The control mechanism of claim 1 wherein said interengageable means comprises a first lever member associated with said choke valve and a second lever member associated with said throttle valve, said first lever member having a formation for engaging a complementary formation on said second lever member when said choke valve is moved from its idling position toward its full speed position and thereby holding said lever members in interengagement in opposition to the respective biasing means. 
     
     
       3. The control mechanism of claim 2 wherein said further means includes a third lever member associated with said throttle valve and means for acting on said third lever member in opposition to said first biasing means for moving said throttle valve toward its full speed position. 
     
     
       4. The control mechanism of claim 1, further including means for moving said choke valve between its cold starting position and its idling position during interengagement of said interengageable means. 
     
     
       5. The control mechanism of claim 2 wherein said choke valve is mounted on a choke valve shaft, said first lever member is rotatable about said shaft and wherein said mechanism further includes a lever non-rotatably mounted on said shaft, said first lever member and said lever having cooperating abutment means allowing said first lever member to move in unison with said lever when pressure is applied to said lever in one direction for moving said choke valve from its idling position into its cold starting position and bringing said first and second lever members into interengagement, said lever being movable independently of said first lever member when said first lever member and said second lever member are interengaged to move said choke valve between its cold starting and full speed positions and said abutment means effecting movement of said lever member and said lever in unison on release of said interengageable means to move said choke valve from its cold starting position to its idling position. 
     
     
       6. The control mechanism of claim 5 wherein said second biasing means comprises a coil spring means surrounding said shaft and acting on said first lever member.